Pollens Ingested by Boll Weevils (Coleoptera: Curculionidae) in Southern Texas and Northeastern Mexico

Abstract

Boll weevils, Anthonomus grandis grandis Boheman, were collected in 1978–1980 from grandlure-baited traps in the Lower Gulf Coast (LGe) and the Lower Rio Grande Valley (LRGV) of southern Texas, and in northeastern Mexico (NEM). The weevils were dissected, and the midgut was removed and examined for the presence of pollen grains. Pollen grains representing 12 families of plants were found in boll weevils from the LRGV, 9 families of plants from the LGC, and 6 families of plants from NEM. The most frequently encountered pollen grains were from plants in the families Poaceae (grasses), Brassicaceae (mustards), and Asteraceae (sunflowers and daisies). Some ingested pollen grains could not be identified. In a separate no-choice study, boll weevils were caged on 22 species of plants during blooming to document pollen feeding. Twenty to 100% of the boll weevils caged on a plant species consumed pollen from that species. These data suggest that adult boll weevils in the field may consume pollen from a wide range of plant species; however, further studies are required to confirm this.